This application is for renewal of a grant for funds to support 5 pre-doctoral and 4 post-doctoral trainees in the Immunology Training Program in Denver. Training is performed at three institutions, at the University of Colorado at Denver (UCD) and its associated Barbara Davis Center for Childhood Diabetes, and at National Jewish Health (NJH). All the faculty on this application are primary or secondary members of the Integrated Department of Immunology which, as its name suggests, is shared between UCD and NJH. The interests of the 28 faculty on this application represent modern immunological research ranging from lymphocyte and myeloid cell development and function to studies on infectious disease and autoimmunity in humans. Indeed, in response to changes in the nature of immunological research and the desires of incoming trainees, several physician scientists have been added to the list of trainers in this renewal application. This grant is headed by Dr. Philippa Marrack, a well known expert in T cell biology who has a long career in training pre- and post-doctoral fellows. She will be helped by Dr. Raul Torres, the Director of the Ph.D. training Program in the Immunology Department and a Steering Committee. Trainees will be chosen from pre- and post-doctoral fellows in the laboratories of any of the faculty on the program. Predoctoral fellows will be appointed after their first year in the program, when they have chosen and begun work in their training laboratories. Both pre- and post-doctoral trainees will be selected, by the Steering Committee, for appointment to the grant based on the merit of their work and their record. Trainees will be required to take a formal course in the Ethics and Conduct of Science and to attend and present in weekly Research in Progress sessions. Attendance at journal clubs, weekly seminars given by invited speakers from around the world and scientific symposia will be encouraged. Trainee advisory committees will meet with the trainees at least twice per year to provide guidance on research and career direction. This program has a long and distinguished record, with almost all its predoctoral trainees continuing to excellent postdoctoral work and most of its pre- and post-doctoral trainees continuing, once they finish their postdoctoral work, with careers in science. The program has seen increasing recruiting of underrepresented minorities trainees over the years and has been, and continues to be, a major focus for immunological research in the Rocky Mountain region in particular and the USA in general.